(Source: eWeek) Cisco forecasts that global cloud data center traffic will grow from 6.0 zettabytes in 2016 to 18.9ZB per year by 2021. Cisco is also projecting that software-as-a-service (SaaS) will be the leading cloud service model through 2021, accounting for 75 percent of cloud workloads. In this slide show, eWEEK looks at some of the …